A measurement signal is supplied via a measurement setup, which typically comprises a probe and a measurement line, to a measuring device, for example, a digital oscilloscope or spectrum analyser. The probe and the measurement line distort the measurement signal dependent upon their transmission function. The distortion of the measurement signal is equalised by an equaliser connected downstream of the measurement setup. The equaliser provides a transmission function which is inverted relative to the transmission function of the measurement setup and, at its output, generates a signal which ideally corresponds to the original measurement signal. While the distortion of the measurement signal is integrated, that is, embedded (English: “embedded”) in the measurement procedure, the equalisation can consequently be designated as a deembedding (English: deembedding).
An equalisation of a measurement signal is typically implemented in blocks using an equalisation filter with a few hundred filter coefficients over a sequence of sampled values of the measurement signal with a block length of a few hundred sampled values. A digital equaliser of this kind is disclosed in US 2003/0109999 A1. The calculation of the equalisation consequently requires a large number of multiplications and additions which significantly limit the real-time capability of the measurement. The object of the invention is therefore to provide an equalisation of a measurement signal in real-time.